1. Technical Field
This invention relates generally to thrust washers or bearing for use in internal combustion engines, and more particularly to three-piece type thrust bearings in which the axially spaced thrust washers are separately made and secured to the associated bearing.
2. Related Art
The thrust washers or bearings for internal combustion engines are typically made as split bearing halves, with each half being formed separately from the other from a respective single piece of bearing material deformed to define an arcuate half bearing and a pair of axially spaced thrust flanges or washers extending radially outwardly of the journal bearing, or alternatively, each formed as a three-piece structure wherein the journal bearing and thrust washer portions are separately formed of the same or different materials and subsequently welded to one another. One-piece flange bearings are costly to manufacture as a number of stamping, forming and bending operations are required. The one-piece construction also limits the selection of materials to be used for the journal bearing and thrust flange portions of the bearing, which typically are of the same material composition since the bearing is made from a single strip of bearing material.
Three-piece thrust bearings are known alternatives to the single-piece type thrust bearings, and have the advantage of enabling the thrust washers to be made of a different material than that of the journal bearing to which they are attached. Typically, the journal bearing is formed along its opposite side edges with a series of notches in which to receive corresponding tabs formed on the thrust washers to prevent the thrust washers from rotating relative to the journal bearing body. The washers are further welded or crimped to prevent relative radial movement of the thrust washers away from the journal bearing on which they are mounted. The requirement of forming notches in the sides of the journal bearings and the additional assembly and securing operations required to hold the thrust washers in place add to the cost and complexity of making such bearings.
It is an object of the present invention to overcome or greatly minimize the inherent limitations of the foregoing thrust washers.